Solution:
I created the following function which switches visual composer tabs by ID.
var setVCTab = function(name) {
var $id = "#"+name;
if ($($id).length > 0) {
setTimeout(function() {
// Clear tabs
$(".vc_tta-tab").each(function(i,a) {
$(a).removeClass("vc_active");
});
// Clear panels
$(".vc_tta-panels").children().each(function() {
$(this).removeClass("vc_active");
});
// Activate Tabs
$(".vc_tta-tabs-list a[href="+$id+"]").each(
function(i,a) { var tab = $(a).closest(".vc_tta-tab"); if (tab) tab.addClass("vc_active");}
);
// Activate Panel
$($id).addClass("vc_active");
location.href = $id;
},1);
}
};
Therefore it should be possible for you to do something like the following.
// Map day indices to tab IDs
var days =["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
// Activate tab for day
setVCTab(days[(new Date()).getDay()]);